public class Example3_6 {
    public static void main(String args[]) {
	double sum=0, item=1;
	int i=1, n=20;
	while(i<n) {
		sum = sum+item;
		i = i+1;
		item = item*(1.0/i);
	}
	System.out.println("sum="+sum);
    }
}
